This is a "Knock Gauge" for a 1986 or 1987 Buick Grand National, T Type, Turbo T, or GNX 3.8 liter turbo V6 which is a perfect item to help you monitor and tune your car.
Detonation is your worst enemy and is the main cause of a blown head gasket, burned pistons or worse. Protect your engine with this unique knock display unit. Designed to fit into a standard 2-1/16 in. gauge opening or gauge pod, the three-color LED display gives you "real time" visual indication of the severity of detonation. Simple 3-wire hookup. Requires the factory ESC module to operate.
